Field of the Invention
The present invention relates to an electrophotographic photosensitive member, a manufacturing method of electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus.
Description of the Related Art
Among electrophotographic photosensitive members, an electrophotographic photosensitive member using an organic photoconductive material has excellent film formability and can be produced by coating, with advantage of achieving an inexpensive electrophotographic photosensitive member at high productivity.
An electrophotographic photosensitive member typically includes a support and a photosensitive layer (a charge generation layer or a hole transporting layer) formed on the support. In order to suppress the charge injection from the support side to the photosensitive layer (charge generation layer) side, inhibit the generation of image defects such as fogging, and conceal the defects on the support surface, an undercoat layer is disposed between the support and the photosensitive layer.
The undercoat layer is required to attain both of extracting electrons from the charge generation layer and suppressing the charge injection from the support side to the charge generation layer side. Both of the extraction of electrons from the charge generation layer and the suppression of the charge injection are required in any environment ranging from low temperature and low humidity to high temperature and high humidity.
In Japanese Patent Application Laid-Open No. H5-88396, an undercoat layer including hydrophobic silica particles for suppression of fluctuation in properties of the undercoat layer due to environmental change is described.
Meanwhile, in Japanese Patent Application Laid-Open No. 2001-83726 and Japanese Patent Application Laid-Open No. 2003-345044, an undercoat layer including an electron transporting material, which better attains both of the extraction of electrons and the suppression of the charge injection, is described. It is presumed that the electron transporting material contained in the undercoat layer improves the extraction of electrons from the charge generation layer and the suppression of the charge injection from the support side to the photosensitive layer side, so that the sensitivity of the photosensitive member can be improved.